1. Technical Field of the Invention
This invention relates generally to a recording medium, such as a tape, and preferably an Advanced Intelligent Tape (“AIT”), for use in an Ultra Fast Backup (“UFB”) format in a fast access data storage system. More particularly, this invention relates to a method and apparatus for recording on a recording medium using a helical scan track write/read technique with a serpentine track pattern to increase the data capacity toward one Terabyte. Still more particularly, this invention relates to a linear sliding scanner with a read/write head stack for performing the helical scan serpentine recording and a method for using the same. Finally, this invention relates to a UFB offset spool cartridge for operatively housing the UFB format recording medium according to the present invention, and a method for loading the same into a tape drive apparatus.
2. Brief Discussion of the Related Art
Currently-available high density recording technology provides high-density, large capacity recording in 8 mm cartridges that are much smaller than other data cartridge formats. AIT cartridges are available that feature a built-in flash memory chip, such as a remote, non-contact, Memory in Cassette (“MIC”) system, for providing key information directed to a drive for the cartridge. Prior efforts by the assignees of this invention have expanded use of the AIT cartridge with the MIC chip to improve reliability, error prediction, and performance in recording and retrieving data on partitioned tape. An example of the use of MIC technology is shown in U.S. Pat. No. 6,611,394. Associated MIC hardware includes a multi-pin interface to the drive or other external connection to store and retrieve selected information directly from the chip to provide real time customer applications.
MIC information consists of data written at the time of cartridge manufacture when the media is first loaded into an AIT drive, portions of the media updated as a part of a recording sequence, and portions of the media that can be written directly by a user's application. A net result is improved access to data when used in conjunction with tape partitioning, reducing, for example, access time up to 50 percent as compared to conventional methods. U.S. Pat. No. 6,674,596, U.S. Pat. No. 6,624,959, and U.S. Pat. No. 6,301,067 are examples of the use of a solid-state memory control of partitioned tape so that it is not necessary to rewind a tape to the beginning when it is desired to record new data.
A current version of AIT cartridges, known as the AIT-3 (a trademark of Sony) is able to hold 100 GB native and up to 260 GB of compressed data, due in part to a use of helical scan recording technology.
Advanced Metal Evaporated (“AME”) is a tape formulation used in AIT installations. Its key characteristics include a 100% pure cobalt magnetic layer design, the absence of binder material to prevent tape head contamination, and a Diamond Like Carbon (“DLC”) protective coating for extreme durability. AME also permits very high-density magnetic recording, thereby allowing the AIT family roadmap to reach large capacity levels.
It remains, however, an overall aim in the art to improve recording capability, such as from 100 GB to a target of 1 Terabyte, a 10 fold increase, building on the technology discussed above, and to increase the speed of access and retrieval of data.
Efforts are known that propose the use of serpentine recording patterns, such as in the multi-track recording technique discussed in U.S. Pat. No. 6,154,334 to Pine, as a time-saving traversal pattern. However, that serpentine traverse has not been previously used in conjunction with helical scanning techniques on flexible recording media.
It is an additional problem in this technology to provide a helical scan recording/playback device capable of achieving a serpentine traverse of the recording media, particularly when the recording media is a flexible media such as a recording tape.